Who woulda thunk it. The No. 1 best-selling book on Amazon theses days is a 700-page tome on global wealth inequality translated from French: Capital in the 21st Century.

The book, written by noted French economist Thomas Piketty, has garnered a heap of praise, especially by leading Western liberals. And it’s helped reignite the debate over income inequality and what the superrich owe to the rest of society. Read Paul Krugman review.

The thesis of Piketty’s book is that investment, or the return on wealth, grows faster than the economy itself. Over time, that widens the gap between the wealthy few and everyone else and leads to a much more unequal society. The rich pass on their wealth to their children and the great families come to dominate the political system because of their economic power.

The man some people are calling a modern-day de Tocqueville or a “rock-star” economist was bound to stir up a counterreaction, of course. Some conservatives have tried to write him off as a latter-day Marx but more thoughtful centrist and center-right thinkers have sought to poke holes in his carefully tailored arguments and reams of historical data.

The title of Clive Crook’s Bloomberg column, for example, is “The Most Important Book Ever is All Wrong.” Crook has plenty of nice things to say about Piketty, but he ultimately thinks the French economist fails to deliver the goods.

“There’s a persistent tension between the limits of the data he presents and the grandiosity of the conclusions he draws. At times this borders on schizophrenia,” Crook writes. “In introducing each set of data, he’s all caution and modesty, as he should be, because measurement problems arise at every stage. Almost in the next paragraph, he states a conclusion that goes beyond what the data would support even if it were unimpeachable.”

The well-known libertarian economist Tyler Cowen takes a different tack in a book review in Foreign Affairs. He argues that the “real issue” is stagnant wages, not wealth inequality.

People don’t care if the rich get richer, Tyler writes, so long as their own wages also go up. The problem in the U.S. now is that wages have leveled off, Cowen notes, but he says Piketty’s book fails to show that wider wealth inequality has caused wages to freeze up.

Cowen also notes that return on investment tends to grow faster than the economy as a whole because rich investors take greater risks, such as investing in new companies with uncertain business prospects. And when those bets go sour, the rich can take a big hit or even lose much of their wealth.

If Piketty has a failure of imagination, though, it’s in his prescription for a uniform global tax on wealthy individuals to prevent them from hiding money in places where tax rates are lower (See: Cayman Islands).

Many Western liberals, especially in Europe, don’t like the idea of competitive tax systems because they believe rich people and big companies exploit the differences to shield their wealth and profits.

Yet such a tax would be unworkable in the U.S. without a constitutional change and Americans would overwhelmingly reject the idea that any domestic tax revenues should be diverted to foreigners. Most Americans don’t even approve of the minuscule amount the U.S. spends on foreign aid.

The U.S. has also had a long-standing history of tax competition between states for jobs and residents. Without that competition, there would be fewer limits on the power of the government to tax. Similarly, nations around the world alter their tax codes to entice global capital and talent.

Few if any nations are likely or willing to give up that “comparative” advantage.